Tension support for circline lamps



Jan. 18, 1955 J. M. PISTEY ETAL 2,700,099

TENSION SUPPORT FOR CIRCLINE LAMPS Filed July 12, 1951 Inventdr-s: John M. Fisteg, William RLVOL/I United States Patent TENSION SUPPORT FOR CIRCLINE LAMPS John M. Pistey and William R. Young, Fairfield, Conn., assignors to General Electric Company, a corporation of New York Application July 12, 1951, Serial No. 236,330

4 Claims. (Cl. 24051.12)

This invention relates to fluorescent lamps and in pariticular to an improved support for a circular fluorescent amp.

Circular fluorescent lamps, in conventional form, are functionally identical to straight fluorescent lamps. That is, they comprise a tubular glass envelope, a pair of filaments, and a gas that glows under predetermined conditions. Instead of having the filament physically displaced by the length of the tube, however, the filament is functionally at opposite ends of the lamp, but physically juxtaposed to permit the lamp to be electrically connected in a circuit through a single electrical fixture. Such an 'electrical fixture customarily is a female receptacle capable both of engaging male prongs extending from the circular lamp and of providing partial support for lamp.

To supplement the support furnished by the fixed electrical fixture, apair of .tensionsupports'are spaced 120 apart, with each being displaced an equal distance from the fixed support. By tension support is meant that particular type of support having a fixed base portion and a deflectible gripping portion spring biased to engage a portion of the lamp. The gripping portion which is arranged to be deflectible relative to the base has a curved face complementing the periphery of a cross section of a portion of the lamp tube. With such a structure, the gripping portion can be deflected radially inwardly relative to the lamp, whereupon the lamp may be positioned to be grasped by the gripping portion of the tension supports when they are released.

A further consideration, with respect to circular lamps is that a certain capacitance is required to facilitate the starting. That is, while the lamp filaments must be heated, so that gas contained in the lamp will be ionized before the lamp can glow, it is desirable to assist this gas ionization by placing capacitors about the lamp at strategic points. It has been found that by placing pieces of metal in contact with the lamp at points coordinated with the position of the tension supports, much better starting effect is given to the lamp.

It is afurther object of this invention then to provide a capacitance effect for the starting of the lamp without impairing unduly the light given by the lamp.

Further objects and advantages of this invention will become apparent and the invention will be more clearly understood from the following description referring to the accompanying drawing and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Briefly, this invention relates to an improved tension support comprising a fixed base portion and a deflectible spring biased gripping portion adapted to engage a circular lamp. The gripping face of the gripping portion is provided with a metal spring which absorbs shock between it and the tension support base and which further provides a capacitance effect for the lamp to aid starting.

Referring to the drawing, Fig. 1 is a bottom plan view of a circular lamp supported on a ceiling surface at three positions; Fig. 2 is a cross-sectional side elevational view taken along the plane aa in Fig. 1 to show a tension support in section; Fig. 3 is a front elevation of the tension support while Fig. 4 is a side View of the same ten sion support.

in the drawing, lamp 1 is shown supported by a fixed support or lampholder 2 and a pair of tension supports 3.

Lamp 1 is one of that type of circular fluorescent lamps 2,700,099 Patented Jan. 18, 1955 ICC comprising a tube curved to have its ends joined at a point (or joint 4) on the periphery of the lamp. Ideally, male electrical prongs (not shown) are brought out at the point 4 to be engageable with the fixed support 2 to electrically connect the lamp in a circuit.

Fixed support 2, which is not an element of this invention conventionally has female receptacle (not shown) which engages the male prongs extending from the joint 4 on the lamp.

A pair of movable or tension supports 3 preferably are spaced apart with each being spaced 120 from the fixed support 2. Each tension support comprises a base 5, a gripping portion 6, a tension spring 7, and a capacitance spring '8, (see Fig. 3). Base 5 which is made of an electrically conducting material is electrically grounded and includes some means for mounting the tension support 3. For example, a threaded aperture 9 is provided to engage a stud 10 to which it is locked by a set screw 11.

Base 5 is further provided with a bearing or pivot pin 12 which provides for support of the gripping portion 6 for deflection relative to the base and with a bushing 13 for supporting tension spring 7 so that it is electrically connected to base 5.

Gripping portion 6 of the tension support has a gripping face 14 shaped to the contour of a section of lamp 1 and it further has an internal recess 15 for engaging the free end of tension spring 7. Recess 15 includes a seat portion 16 which engages the end of spring '7 opposite that held by bushing 13. With the structure provided by the seat 16 and the bushing 13, a secure position is provided for the tension spring 7 whereby it biases the gripping portion 6 of the tension clockwise about pin 12 as viewed from Fig. 2.

Capacitance spring is interposed between the gripping face 14 and the lamp 1, as is seen in Fig. 2, and when the lamp is removed from the supports, the capacitance spring 8 is normally deflected slightly away from the gripping face 14 as shown in Fig. 3. Spring 8 has a face portion 17, a flat surface 18, a stop portion 19, and a securing portion 20.

Face portion 17 can have any shape and area, but it has been found that an area that conforms with the inner face 14 of the gripping portion 6 has a desirably capacitive effect for starting. With such a contour, the metal surface is hidden by the gripping portion 6.

Stop portion 19 of spring 8, like face portion 17, is deflected out of contact with both base 5 and gripping portion 6 when the gripping portion is cocked back to allow the removal of the lamp. Consequently when gripping portion 6 is flicked, the stop portion 19 of spring 8 strikes the base 5 and absorbs some of the shock before the gripping portion 6 assumes its final resting position. It has been found that stop portion 19 thereby prevents breakage of the gripping portion 6 adjacent its pivotal axis.

Spring 8, therefore, serves the dual function of providing a stop portion 19 which absorbs shock between the gripping portion 6 and base 5 and it further provides a capacitance effect required to aid lamp starting.

The securing portion 20 of spring 8 can be of any desired shape but it has been found that by providing it with a hook 21 which fits under the spring 7 to extend axially therewith, the spring 8 is satisfactorilv anchored in an economical manner. This structure also assures the fact that face portion 17 which is to provide the capacitive starting effect is electrically grounded.

Modifications of this invention will occur to those skilled in the art and it is desired to be understood, therefore, that this invention is not intended to be limited to the particular embodiment disclosed but rather it is intended to cover all modifications which are within the true spirit and scope of this invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A tension support for a circular tubular fluorescent lamp comprising an electrically conducting base portion adapted to be mounted on a lamp fixture and an insulating gripping portion having a curved contour with a concave surface which is shaped to engage a portion of the cross-sectional periphery of the lamp, means pivotally mounting said gripping portion on said base member, and spring means interposed between said base and said gripping portion for moving said gripping portion about its pivot and into engagement with a lamp, a stop means for limiting the pivotal movement of said gripping portion under the action of the spring, and a thin sheet of spring metal positioned in front of said concave surface of the gripping portion for engagement with the glass surface of the lamp and having a portion in contact with said electrically conducting base member, so as to produce a capacitance effect to assist the starting of the lamp.

2. A tension support for a circular tubular fluorescent lamp comprising an electrically conducting base portion adapted to be mounted on a lamp fixture and an insulating gripping portion having a curved contour With a concave surface which is shaped to engage a portion of the cross-sectional periphery of the lamp, means pivotally mounting said gripping portion on said base member, and a compression spring interposed between said base and said gripping portion for moving said gripping portion about its pivot and into engagement with a lamp, a stop means on said gripping portion for engaging said base to limit the pivotal movement of said gripping portion under the action of the spring, and a thin sheet of spring metal positioned in front of said concave surface of the gripping portion for engagement with the glass surface of the lamp, the said sheet spring further being interposed between the stop means of the gripping portion and said base member and finally being attached to the said electrically conducting base member, so as to produce a capacitance effect to assist the starting of the lamp.

3. A tension support as recited in claim 2 wherein the sheet spring is provided with a hook-end which engages under the said compression spring so that the spring is firmly attached to the base.

4. A tension support for a circular tubular fluorescent lamp comprising an electrically conducting base portion adapted to be mounted on a lamp fixture and an insulating gripping portion having a curved contour with a concave surface which is shaped to engage a portion of the cross-sectional periphery of the lamp, means pivotally mounting said gripping portion on said base member, and spring means interposed between said base and said gripping portion for moving said gripping portion about its pivot and into engagement with the lamp, a stop means on said gripping portion for engaging said base to limit the pivotal movement of said gripping portion under the action of the spring, and a thin sheet of spring metal positioned in front of said concave surface of the gripping portion for engagement with the glass surface of the lamp, and having a portion interposed between the stop means of the gripping portion and said base so as to cushion the shock when the pivotal movement of the gripping portion is abruptly halted at the end of its stroke, and further having a portion in contact with said electrically conducting base member so as to produce a capacitance effect to assist the starting of the lamp.

References Cited in the file of this patent UNITED STATES PATENTS 2,279,866 Ellinwood Apr. 14, 1942 2,331,258 White et al Oct. 5, 1943 2,480,765 Pieper Aug. 30, 1949 2,534,956 Pistey et al Dec. 19, 1950 FOREIGN PATENTS 485,212 Germany Oct. 28, 1929 

